X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=ffmpeg_capture.cpp;h=5474c52fd94f511491206e4f8a92b2545bc87475;hb=f07adb19f0e2571bf4894ec57e6fcfe4a3e5fd95;hp=647b7cbea4b4a96e25b1496b66a0b2b5d476d335;hpb=bcdbb7bdfcfc45b34ccdf36d3950e7e0af6444bd;p=nageru

diff --git a/ffmpeg_capture.cpp b/ffmpeg_capture.cpp
index 647b7cb..5474c52 100644
--- a/ffmpeg_capture.cpp
+++ b/ffmpeg_capture.cpp
@@ -36,6 +36,16 @@ using namespace std;
 using namespace std::chrono;
 using namespace bmusb;
 
+namespace {
+
+steady_clock::time_point compute_frame_start(int64_t frame_pts, int64_t pts_origin, const AVRational &video_timebase, const steady_clock::time_point &origin, double rate)
+{
+	const duration<double> pts((frame_pts - pts_origin) * double(video_timebase.num) / double(video_timebase.den));
+	return origin + duration_cast<steady_clock::duration>(pts / rate);
+}
+
+}  // namespace
+
 FFmpegCapture::FFmpegCapture(const string &filename, unsigned width, unsigned height)
 	: filename(filename), width(width), height(height)
 {
@@ -68,7 +78,7 @@ void FFmpegCapture::start_bm_capture()
 		return;
 	}
 	running = true;
-	producer_thread_should_quit = false;
+	producer_thread_should_quit.unquit();
 	producer_thread = thread(&FFmpegCapture::producer_thread_func, this);
 }
 
@@ -78,7 +88,7 @@ void FFmpegCapture::stop_dequeue_thread()
 		return;
 	}
 	running = false;
-	producer_thread_should_quit = true;
+	producer_thread_should_quit.quit();
 	producer_thread.join();
 }
 
@@ -107,17 +117,17 @@ void FFmpegCapture::producer_thread_func()
 	snprintf(thread_name, sizeof(thread_name), "FFmpeg_C_%d", card_index);
 	pthread_setname_np(pthread_self(), thread_name);
 
-	while (!producer_thread_should_quit) {
+	while (!producer_thread_should_quit.should_quit()) {
 		string pathname = search_for_file(filename);
 		if (filename.empty()) {
 			fprintf(stderr, "%s not found, sleeping one second and trying again...\n", filename.c_str());
-			sleep(1);
+			producer_thread_should_quit.sleep_for(seconds(1));
 			continue;
 		}
 		if (!play_video(pathname)) {
 			// Error.
 			fprintf(stderr, "Error when playing %s, sleeping one second and trying again...\n", pathname.c_str());
-			sleep(1);
+			producer_thread_should_quit.sleep_for(seconds(1));
 			continue;
 		}
 
@@ -179,13 +189,40 @@ bool FFmpegCapture::play_video(const string &pathname)
 	unique_ptr<AVCodecContext, decltype(avcodec_close)*> codec_ctx_cleanup(
 		codec_ctx.get(), avcodec_close);
 
+	int64_t pts_origin = 0, last_pts = 0;
 	steady_clock::time_point start = steady_clock::now();
+	steady_clock::time_point next_frame_start = start;
+	double rate = 1.0;
 
 	unique_ptr<SwsContext, decltype(sws_freeContext)*> sws_ctx(nullptr, sws_freeContext);
 	int sws_last_width = -1, sws_last_height = -1;
 
 	// Main loop.
-	while (!producer_thread_should_quit) {
+	while (!producer_thread_should_quit.should_quit()) {
+		// Process any queued commands from other threads.
+		vector<QueuedCommand> commands;
+		{
+			lock_guard<mutex> lock(queue_mu);
+			swap(commands, command_queue);
+		}
+		for (const QueuedCommand &cmd : commands) {
+			switch (cmd.command) {
+			case QueuedCommand::REWIND:
+				if (av_seek_frame(format_ctx.get(), /*stream_index=*/-1, /*timestamp=*/0, /*flags=*/0) < 0) {
+					fprintf(stderr, "%s: Rewind failed, stopping play.\n", pathname.c_str());
+				}
+				pts_origin = last_pts = 0;
+				start = next_frame_start = steady_clock::now();
+				break;
+
+			case QueuedCommand::CHANGE_RATE:
+				start = next_frame_start;
+				pts_origin = last_pts;
+				rate = cmd.new_rate;
+				break;
+			}
+		}
+
 		// Read packets until we have a frame or there are none left.
 		int frame_finished = 0;
 		AVFrameWithDeleter frame = av_frame_alloc_unique();
@@ -226,6 +263,7 @@ bool FFmpegCapture::play_video(const string &pathname)
 				fprintf(stderr, "%s: Rewind failed, not looping.\n", pathname.c_str());
 				return true;
 			}
+			pts_origin = last_pts = 0;
 			start = steady_clock::now();
 			continue;
 		}
@@ -252,8 +290,8 @@ bool FFmpegCapture::play_video(const string &pathname)
 		video_format.has_signal = true;
 		video_format.is_connected = true;
 
-		const duration<double> pts(frame->pts * double(video_timebase.num) / double(video_timebase.den));
-		const steady_clock::time_point frame_start = start + duration_cast<steady_clock::duration>(pts);
+		next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
+		last_pts = frame->pts;
 
 		FrameAllocator::Frame video_frame = video_frame_allocator->alloc_frame();
 		if (video_frame.data != nullptr) {
@@ -261,7 +299,7 @@ bool FFmpegCapture::play_video(const string &pathname)
 			int linesizes[4] = { int(video_format.stride), 0, 0, 0 };
 			sws_scale(sws_ctx.get(), frame->data, frame->linesize, 0, frame->height, pic_data, linesizes);
 			video_frame.len = video_format.stride * height;
-			video_frame.received_timestamp = frame_start;
+			video_frame.received_timestamp = next_frame_start;
 		}
 
 		FrameAllocator::Frame audio_frame;
@@ -269,7 +307,7 @@ bool FFmpegCapture::play_video(const string &pathname)
                 audio_format.bits_per_sample = 32;
                 audio_format.num_channels = 8;
 
-		this_thread::sleep_until(frame_start);
+		producer_thread_should_quit.sleep_until(next_frame_start);
 		frame_callback(timecode++,
 			video_frame, 0, video_format,
 			audio_frame, 0, audio_format);